Close file handle on exceptions during connect

Closes gh-32423

spring-boot-project/spring-boot-tools/spring-boot-buildpack-platform/src/main/java/org/springframework/boot/buildpack/platform/socket/DomainSocket.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -69,8 +69,14 @@ public abstract class DomainSocket extends AbstractSocket {
 
 	private FileDescriptor open(String path) {
 		int handle = socket(PF_LOCAL, SOCK_STREAM, 0);
-		connect(path, handle);
-		return new FileDescriptor(handle, this::close);
+		try {
+			connect(path, handle);
+			return new FileDescriptor(handle, this::close);
+		}
+		catch (RuntimeException ex) {
+			this.close(handle);
+			throw ex;
+		}
 	}
 
 	private int read(ByteBuffer buffer) throws IOException {